Combination air conditioner and heater

ABSTRACT

A combination air conditioner and heater includes an air blower having a housing in which electric heating elements are mounted. The air blower is mounted within an outer casing which is provided with an air inlet and an air outlet, and air cooling means are positioned in the casing between the air inlet and the blower. The blower creates a path of air flow from the air inlet to the air outlet, and the cooling means and the heating means can be selectively activated to either cool or heat the air which passes through the casing.

United States Patent 1191 1111 3,865,182

Blossom Feb. 11, 1975 COMBINATION AIR CONDITIONER AND 3,035,146 5/1962 Pryor 219/369 HEATER 3,228,459 H1966 CIOOkCI CI "11 5 i65/64 3,367,408 2/1968 Moreland 165/27 [75] Inventor: Armond L. Blossom, Wichita, Kans. [73] Assignee: The Coleman Company, Wichita, Emminerchflrles sukalo Kans. [22] Filed: Aug. 30, 1973 [57] I ST A combination a1r cond1t1oner and heater 1ncludes an PP N03 393,124 air blower having a housing in which electric heating elements are mounted. The air blower is mounted 52 us. c1 165/27, 165/50, 165/64, Within an Outer easing Whieh is provided with an air 219/369 inlet and an air outlet, and air cooling means are posi- 1511 Int. 0. F25b 29/00 tiehed in the easing between the air inlet and the [53] Field of Search H 165/18, 60, 22, 27, 5Q, blower. The blower creates a path of air flow from the 165/48 219/369 air inlet to the air outlet, and the cooling means and the heating means can be selectively activated to ei- [56] References Cited ther cool or heat the air which passes through the cas- UNITED STATES PATENTS 2,813,406 11 1957 Smith I65/50 l Claim14 Drawing Figures 0 m 21 \\|1 .\\III II I 1, 6

M n, fluu, 2| \\\11,, 22 37 111111,,

.PATENTED 3 855 182 SHEET 10F 2 PATENTEB FEB] 1 I975 SHEET 2 OF 2 COMBINATION AIR CONDITIONER AND HEATER BACKGROUND This invention relates to a combination air conditioner and heater, and, more particularly, to a combination air conditioner and heater in which the heating elements are located within the air blower.

The invention finds particularly utility in connection with forced air heating and cooling systems for dwellings, particularly dwellings such as mobile homes. Forced air air conditioning systems are available for mobile homes which include a self-contained unit which can be located outside of the home and which includes both the cooling coil and the condenser coil. This provides a compact unit which does not occupy any space within the home, and the condenser coil can be cooled outside of the home as in standard forced air air conditioning systems. Air supply and air return ducts carry conditioned air from the unit to the home and return air to the unit for conditioning.

Homes which are equipped with heating units often have the heating unit located within the home. While this has the advantage of protecting the heating unit from the weather, the heating unit does occupy space within the home which might be better put to other uses.

Some attempts have been made to provide separate heating units as accessories or attachments to selfcontained air conditioning units which are located outside the home, but such heating units are subject to several problems. For example, an electrical heating unit which is located outdoors is subject to short circuiting or damage by water which may leak into the heating unit. For this reason no heating unit which is provided as an attachment or accessory to a self-contained air conditioning unit has, to my knowledge, received the approval of Underwriters Laboratories. Further, the addition of a separate heating unit to the air conditioning unit increases the space which is required for the combined heating and air conditioning system.

Air blowers have been provided in the past which are equipped with heating elements, but such blowers have not been combined with an air conditioner to provide a self-contained combination air conditioner and heater.

SUMMARY The invention provides a self-contained combined heater and air conditioner by incorporating the heating elements within the blower of the combined unit. The combined self-contained unit can be located outside of the building which is to be heated or cooled, and, since the unit is self-contained, it can be made sufficiently weatherproofto provide safe operation. Since the heating elements are mounted within the air blower. the heater does not occupy additional space, and the unit can be provided either as an air conditioning unit or as a combination air conditioning and heating unit by using an air blower which is either equipped or not equipped with heating elements. If desired, the air blower can be equipped with a two-speed motor and the electrical controls for the air unit can automatically switch the motor to the lower speed when the heating elements are activated to provide sufficient heat exchange with the air passing over the heating elements.

DESCRIPTION OF THE DRAWING The invention will be explained with in conjunction with an illustrative embodiment shown in the accompanying drawing, in which FIG. 1 is a fragmentary perspective view of a combination air conditioner and heater formed in accordance with the invention which is connected to a mobile home for supplying cooled or heated air to the home;

FIG. 2 is a fragmentary perspective view. partially broken away, of the combination air conditioner and heater of FIG. I;

FIG. 3 is a fragmentary side elevational view. partially in section. ofthe combination air conditioner and heater showing the air blower; and

FIG. 4 is a fragmentary view taken along the line of 44 of FIG. 3.

DESCRIPTION OF SPECIFIC EMBODIMENT Referring first to FIG. 1, the numeral 10 designates generally a combination air conditioning and heating unit for cooling or heating a mobile home 11. The mobile home includes an outside wall 12 which extends upwardly from a floor l3, and the home is supported on the ground G in the conventional manner. Temporary panels I4 extend from the floor to the ground for enclosing the space beneath the mobile home while it remains in place.

The home is equipped with a conventional forced air supply and return system which includes supply ducts l5 and supply grates l6 and air return grates 17. Air is supplied from the air conditioning and heating unit by supply ducts I8, and air is returned from the home to the air conditioning and heating unit by return ducts 19.

The air conditioning and heating unit 10 includes an outer box-like casing 21 which is attached to a base 22 which rests on the ground outside of the home. The casing includes a generally retangularly extending side wall 23 and a cover 24 which has a downwardly extending perimetric flange 25 for sealing the enclosure within the casing. The cover is suitably secured to the side wall, as by sheet metal screws, and, if desired, a weatherproof gasket can be secured therebetween.

Referring now to FIG. 2, the side wall 23 of the casing is provided with a rectangular inlet opening 26 and a rectangular outlet opening 27. The air return duct I9 is connected to the inlet opening 26 by means of a conventional connecting box 28 which is secured to the side wall of the casing around the inlet opening and which includes a collar 29 over which the duct can be inserted and secured. A similar connecting box 30 is secured to the casing around the air outlet 27 for attaching the air supply duct 18.

The casing includes an internal partition 32 which divides the enclosure of the casing into a cooling compartment 33 which is provided with the air inlet 26 and air outlet 27 and a condenser and compressor compartment 34. A conventional closed refrigerant system is mounted within the casing, and the system includes an evaporator or cooling coil 35 mounted within the cooling compartment 33 just inwardly of the air inlet 26, a condenser coil 36 mounted within the condenser and compressor compartment 34, and a compressor (not shown) which is also mounted within the condenser and compressor compartment 34. The closed refrigerant system operates in the conventional manner to circulate refrigerant from the compressor through the condenser and evaporator coils. The condenser and compressor compartment is ventilated by grilles 37 (FIG. 1) which are provided in the side wall of the casing adjacent the condenser coils, and an exhaust fan 38 is mounted on the cover of the casing to draw outside air through the grilles 37 and past the condenser coils to cool the condenser coils.

An air blower 41 is mounted within the cooling compartment 33 between the evaporator or cooling coil 35 and the air outlet 27 to draw air through the air inlet and the cooling coil and to force air outwardly through the air outlet 27 and into the supply duct 18. The particular air blower illustrated is a conventional squirrelcage blower which includes a blower housing or scroll 42, an electric motor 43 mounted on the scroll, and a cylindrical vane-equipped blower wheel 44 rotatably supported within the scroll by the motor.

Referring to FIGS. 3 and 4, the scroll 42 includes a pair of flat side walls 45 and 46 and a curved central wall 47 which extends between the flat side walls. An air inlet opening 48 (FIG. 2) is provided through the side wall 45 and a motor opening 49 (FIG. 3) is provided through the side wall 46. The motor is mounted within the opening 49 by a spider support bracket 50 which is secured to the side wall 46, and the blower wheel 44 is mounted on the drive shaft of the motor coaxially withthe openings 48 and 49.

The central wall 47 includes a straight lower end portion 51 which is separated from the upper end 52 of the central wall to form a rectangular outlet opening 53 between the forward portions of the side walls. The inlet opening 48 of the housing communicates the cooling chamber 33 with the center of the blower wheel, and the outlet opening 53 of the blower housing is positioned adjacent the air outlet 27 of the casing. A rectangular attaching flange 54 is secured to the lower housing around the outlet opening, and the blower housing is secured to the casing by means of the attaching flange 54 and a support bracket 55 which extends between the bottom of the lower housing and the casmg.

The curved central wall 47 of the scroll extends slightly eccentrically relative to the axis of the blower wheel and the distance of the curved wall from the axis of the blower wheel increases from the upper edge 52 of the central wall to the straight portion 51 to provide an air flow channel between the blower wheel and the central wall for guiding air to the outlet 53. As the blower wheel rotates, thevanes 56 of the wheel draw air through the inlet opening 48 and force the air outwardly through the vanes against the curved wall 47 and out through the outlet opening.

A plurality of elongated heating elements 57 are secured to the central wall 47 ofthe scroll and are formed to the contour of the central wall so that the air which is forced against the central wall intimately contacts the heating elements. In the embodiment illustrated, the heating elements comprise six calrod heating rods which are spaced along the width of the central wall and which extend from about oclock as viewed in FIG. 3 to about 7 o'clock. Other types of heating elements can also be used. For example, a plurality of heating strips or rods which extend axially with respect to the blower wheel can be spaced around the inside periphery of the central wall 47.

The upper ends of the heating elements extend upwardly through the central wall 47 at 59 (FIG. 3) and are connected by wires 60 to control means 61. The control means 61 are mounted within a control box 62 secured to the top of the blower housing. The blower motor 43 and the compressor of the air conditioning system may also be connected to the control mean 61, and the control means is connected by-wires 63 to another control means 64 (FIG. 3) mounted within the mobile home.

The control means 61 and 64 are conventional and permit the compressor, blower motor, and heating elements to be energized when desired while preventing activation of both the compressor and the heating ele-.

ments simultaneously. The blower motor may be capable of operating at two or more speeds, and the control means advantageously switch the blower motor to a lower speed when the heating elements are energized so that the air passes over the heating elements at a slower rate, thereby permitting more efficient heat exchange between the heating elements and the air.

When the unit 10 is to be used to cool the air in the mobile home, the blower motor and the compressor are activated by the control means, and the blower draws air through the return duct 19 and through the evaporator coil 35 which is being supplied with liquid refrigerant by the closed refrigerant system to cool the air. The air is then forced through the blower wheel and through the outlet opening 27 of the casing, through the supply duct 18, and through the supply grates 16 in the home. If air circulation is desired without cooling, the control means can be operated to shut off the compressor while the blower motor continues to operate.

When it is desired to heat the mobile home, the control means are operated to energize the blower motor and the heating elements. The blower again draws air through the return duct 19 and through the cooling coil 35 into the cooling chamber 33. However, since the compressor is not operating, the evaporator coil 35 does not cool the incoming air. The air is then forced outwardly by the blower wheel against the central wall 47 and the heating elements 57, and the air is heated as it flows over the heating elements and the central wall 47. The heated air is then forced through the outlets of the blower housing and the casing and through the supply duct 18.

The unit 10 can be adapted for cooling only by using a blower which is identical to the blower 41 but which is not equipped with heating elements. The same blower housing is used whether or not it is equipped with the heating elements, and the addition of the heating elements does not require any additional space or any attachment to the casing which can affect the operation of the heater.

Although I have described the motor as being mounted on the scroll, it can be mounted separately from the blower housing and connected to the blower wheel by drive belts or the like.

While in the foregoing specification a detailed de- I claim:

1. In combination with a mobile home, an air conditioner unit mounted on the ground outside of and separate from said mobile home, said unit including a casing providing a weatherproof compartment having an air inlet and an air outlet, duct means secured to each of the air inlet and the air outlet and connected to said mobile home, an air blower mounted in said compartment, the air blower comprising a blower housing having an air inlet and an air outlet, an air guide surface for directing air from the inlet to the outlet, and a blower wheel rotatably mounted within the blower housing for forcing air over the air guide surface and through the air outlets of the blower housing and the casing, power means within the casing for rotating the blower wheel, and cooling means mounted within said compartment between the air inlet of the compartment and the air inlet of the air blower for cooling the air passing through the air inlet of the air blower, wherein the im provement comprises: electric heating elements secured to the blower housing adjacent the air guide surface for heating the air passing over the air guide surface, control means for selectively activating the heating means or the cooling means, said power means comprising a two-speed motor which is operable at a relatively high speed and a relatively low speed, said control means including means for operating said motor at the low speed when the heating means is activated. 

1. In combination with a mobile home, an air conditioner unit mounted on the ground outside of and separate from said mobile home, said unit including a casing providing a weatherproof compartment having an air inlet and an air outlet, duct means secured to each of the air inlet and the air outlet and connected to said mobile home, an air blower mounted in said compartment, the air blower comprising a blower housing having an air inlet and an air outlet, an air guide surface for directing air from the inlet to the outlet, and a blower wheel rotatably mounted within the blower housing for forcing air over the air guide surface and through the air outlets of the blower housing and the casing, power means within the casing for rotating the blower wheel, and cooling means mounted within said compartment between the air inlet of the compartment and the air inlet of the air blower for cooling the air passing through the air inlet of the air blower, wherein the improvement comprises: electric heating elements secured to the blower housing adjacent the air guide surface for heating the air passing over the air guide surface, control means for selectively activating the heating means or the cooling means, said power means comprising a two-speed motor which is operable at a relatively high speed and a relatively low speed, said control means including means for operating said motor at the low speed when the heating means is activated. 